How long will it be before New Orleans is itself again? You hear estimates: three more weeks before it's dry, at least two months for electricity, but a plausible answer is never. Vast tracts of the city--not just shanties but mansions, not just the morgue but the Southern Yacht Club--aren't salvageable. They all sit in what is called "floodwater" but is really a solution of oil, feces, battery acid, human and animal rot, burst containers of bug spray and paint thinner and nail polish and antifreeze. The primary...